yes double connects at both ends and you need a uv protection under the bulb mogul base aka single end bulbs have it built in to the bulb other then that nothing really other then being smaller then mogul based bulbs.
I run single end or mogul base same thing as I don't want the extra issue of maintaing a extra piece of glass. radium 20ks and on my 240 14k I forgot which brand coralvue I think